The production of a spiro[cyclopentane]quinolinedione is described in Chem. Pharm. Bull., 17, 1290 (1969). Several additional spiroquinoline diones are disclosed in Bull. Soc. Chim. Fr., 364 (1968). The references do not describe pharmaceutical uses for these compounds.
The compounds employed in the present application are disclosed in European published application No. 84 11 4974 published June 19, 1985. That application does not disclose the compounds for use in the treatment of hyperproliferative skin disease.